Marsico Nuovo (Lucano: Màrsc) is a town and comune of the province of Potenza in the Basilicata region of southern Italy.

It is an agricultural centre in the Agri river valley.

The city's origins are obscure, but, after the destruction by the Saracens of the ancient Grumentum, the town grew in importance, and became the seat of a county under the Normans (11th century).

It was subsequently ruled by the Hauteville, the Guarna and Sanseverino families.

The last count from the latter, Ferrante Sanseverino, was exiled in 1552 and his fiefs acquired by the Kingdom of Naples.